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Adrian George
Asked: 2015-01-13 13:30:36 +0800 CST

How can I refer to all files that are named using two numbers?

  • 772

I want to make a shell script that downloads all files that area named [0-9][0-9].png;

e.g: 00.png 01.png 33.png 91.png etc

files = ???????

for file in files
do

curl ftp://server/${file}

done

What should I put at files = ???

scripts

3 Answers

  1. I'd be highly surprised if the ftp://server/file protocol permits wildcards. I suspect you'll have to fetch a list of the available files and iterate over the ones with 2 digits.

    However if you want to generate the numbers 00 to 99 in bash:

    for file in {0..9}{0..9}.png; do ...
    • 4

  2. Use Bash's filename expansion (using *, ? and []):

    $ ls
00.png  03.png  06.png  09.png  12.png  15.png  18.png  21.png
01.png  04.png  07.png  10.png  13.png  16.png  19.png
02.png  05.png  08.png  11.png  14.png  17.png  20.png
$ files=([0-9][0-9].png)
$ echo "${files[@]}"
00.png 01.png 02.png 03.png 04.png 05.png 06.png 07.png 08.png 09.png 10.png 11.
png 12.png 13.png 14.png 15.png 16.png 17.png 18.png 19.png 20.png 21.png

    This, unlike {0..9}{0..9}.png, only expands to existing filenames. So you could do:

    files=([0-9][0-9].png)   # creates an array

for FILE in "${files[@]}"
do
    curl "ftp://server/${FILE}"
done

    Or, directly:

    for FILE in [0-9][0-9].png    
do
    curl "ftp://server/${FILE}"
done
    • 2

  3. seq prints a sequence of numbers. -w equalizes width by padding with leading zeroes.

    files=`seq -w 0 99`

for file in $files
do

curl ftp://server/${file}.png

done
    • 1